linux/kernel/power
Jonas Meurer c052bf82c6 PM: suspend: Add sysfs attribute to control the "sync on suspend" behavior
The sysfs attribute `/sys/power/sync_on_suspend` controls, whether or not
filesystems are synced by the kernel before system suspend.

Congruously, the behaviour of build-time switch CONFIG_SUSPEND_SKIP_SYNC
is slightly changed: It now defines the run-tim default for the new sysfs
attribute `/sys/power/sync_on_suspend`.

The run-time attribute is added because the existing corresponding
build-time Kconfig flag for (`CONFIG_SUSPEND_SKIP_SYNC`) is not flexible
enough. E.g. Linux distributions that provide pre-compiled kernels
usually want to stick with the default (sync filesystems before suspend)
but under special conditions this needs to be changed.

One example for such a special condition is user-space handling of
suspending block devices (e.g. using `cryptsetup luksSuspend` or `dmsetup
suspend`) before system suspend. The Kernel trying to sync filesystems
after the underlying block device already got suspended obviously leads
to dead-locks. Be aware that you have to take care of the filesystem sync
yourself before suspending the system in those scenarios.

Signed-off-by: Jonas Meurer <jonas@freesources.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-01-16 21:47:03 +01:00
..
autosleep.c PM / wakeup: Show wakeup sources stats in sysfs 2019-08-21 00:20:40 +02:00
console.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
energy_model.c sched/topology: Remove unused 'sd' parameter from arch_scale_cpu_capacity() 2019-06-24 19:23:39 +02:00
hibernate.c PM: hibernate: Add more logging on hibernation failure 2020-01-07 13:31:12 +01:00
Kconfig PM: suspend: Add sysfs attribute to control the "sync on suspend" behavior 2020-01-16 21:47:03 +01:00
main.c PM: suspend: Add sysfs attribute to control the "sync on suspend" behavior 2020-01-16 21:47:03 +01:00
Makefile PM: Introduce an Energy Model management framework 2018-12-11 15:16:58 +01:00
power.h y2038: syscalls: change remaining timeval to __kernel_old_timeval 2019-11-15 14:38:29 +01:00
poweroff.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 248 2019-06-19 17:09:08 +02:00
process.c PM / sleep: Show freezing tasks that caused a suspend abort 2018-09-10 12:09:10 +02:00
qos.c PM / QoS: Restore DEV_PM_QOS_MIN/MAX_FREQUENCY 2019-11-29 12:04:50 +01:00
snapshot.c PM: hibernate: fix spelling mistake "shapshot" -> "snapshot" 2020-01-10 12:15:30 +01:00
suspend_test.c PM: sleep: Switch to rtc_time64_to_tm()/rtc_tm_to_time64() 2019-12-20 09:58:08 +01:00
suspend.c PM: suspend: Add sysfs attribute to control the "sync on suspend" behavior 2020-01-16 21:47:03 +01:00
swap.c kernel: power: swap: use kzalloc() instead of kmalloc() followed by memset() 2019-06-28 10:20:39 +02:00
user.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
wakelock.c PM / wakeup: Show wakeup sources stats in sysfs 2019-08-21 00:20:40 +02:00